@charset 'UTF-8';

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f7fa;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 20px;
}

.header {
    background: #2c3e50;
    color: white;
    padding: 20px 20px;
    border-radius: 8px 8px 0 0;
}

.header h1 {
    font-size: 22px;
    font-weight: 500;
    text-align: center;
}

.card {
    background: white;
    border-radius: 0 0 8px 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    padding: 20px;
}

.progress {
    margin-bottom: 20px;
    padding: 10px;
    background: #f8f9fa;
    border-radius: 5px;
    font-size: 14px;
}

.question-section {
    margin-bottom: 30px;
}

.section-title {
    font-size: 18px;
    margin-bottom: 15px;
    color: #2c3e50;
    padding-bottom: 5px;
    border-bottom: 1px solid #eee;
}

.question {
    margin-bottom: 25px;
    padding: 15px;
    border: 1px solid #e1e4e8;
    border-radius: 5px;
    transition: all 0.3s;
}

.question:hover {
    border-color: #3498db;
}

.question p {
    margin-bottom: 12px;
    font-weight: 500;
}

.options {
    margin-left: 10px;
}

.option {
    margin-bottom: 8px;
    display: flex;
    align-items: center;
}

.option input {
    margin-right: 10px;
    width: 16px;
    height: 16px;
}

.option label:hover {
    cursor: pointer;
}

.option.correct {
    color: #27ae60;
    font-weight: bold;
}

.option.incorrect {
    color: #e74c3c;
}

.btn-group {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 30px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
}

.btn-primary {
    background: #3498db;
    color: white;
}

.btn-primary:hover {
    background: #2980b9;
}

.btn-secondary {
    background: #95a5a6;
    color: white;
}

.btn-secondary:hover {
    background: #7f8c8d;
}

.result {
    margin-top: 20px;
    padding: 15px;
    border-radius: 5px;
    display: none;
}

.result.show {
    display: block;
}

.correct-answer {
    margin-top: 5px;
    color: #27ae60;
    font-weight: bold;
}

.explanation {
    margin-top: 10px;
    padding: 10px;
    background: #e8f4fd;
    border-left: 3px solid #3498db;
    font-size: 14px;
    display: none;
}

.explanation.show {
    display: block;
}

.question-number {
    display: inline-block;
    width: 24px;
    height: 24px;
    line-height: 24px;
    text-align: center;
    background: #3498db;
    color: white;
    border-radius: 50%;
    margin-right: 8px;
}